Boomerang

ABSTRACT

The present invention discloses a boomerang, which comprises a flight component, a central shaft and a protective device, wherein the flight component comprises at least one rotating device and a driving device; The center of the shaft runs through the center axis of the maximum diameter plane formed when the rotating device rotates, and the protective device is composed of a plurality of ribs connected with each other and arranged around the flight component. The boomerang is safer in use, better in flying performance, more ornamental and playable.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of the serial number of U.S. patentapplication Ser. No. 17/426,083, filed on Apr. 8, 2021, entitledBoomerang, the entire disclosure of which is incorporated herein

TECHNICAL FIELD

The present invention relates to the technical field of boomerangs, inparticular to a boomerang.

BACKGROUND

The moment to the supporting point generated by the gyro rotating athigh speed by gravity will not make it topple, but process at a smallangle, which is the gyro effect. Simply put, the gyro effect means thatthe rotating object has inertia to keep its rotating direction.

Gyro effect is widely used in technical fields such as scientific andtechnological progress, and its practical application can be seen fromaerospace to deep-sea stealth. In our daily life, a flying toy that canfly back after being thrown is one of the most representative practicalapplications of gyro effect.

Most of the rotary flying toys in the prior art adopt two pairs ofpropellers which are arranged in parallel and rotate in oppositedirections to offset the torque generated by the rotation of thepropellers, so as to provide the lifting force of the flying toys andincrease the stability of the flying toys. U.S. Pat. No. 6,843,699discloses a directional controllable aircraft and a propeller structurefor realizing the same, which comprises a main propeller connected to acentral hub, the main propeller including a pair of propeller finsextending from a propeller shaft, a plurality of hub fins fixed to thecentral hub and extending outward and downward from the central hub, themain propeller and the plurality of hub fins rotating in oppositedirections caused by torque of a motor structure for rotating the mainpropeller, The hub fins extend from the central hub to the outer ring,and the main propeller extends downward from the central hub and ispositioned below the hub fins so that the tail end of the main propelleris located inside the outer ring. The propeller also includes a pair ofconnections connecting the propeller to the propeller shaft fixed to thedrive shaft. When the torque of the rotor structure changes, the pitchand height of the propeller fins also change so as to substantiallyoffset the tail end tilt.

However, although the flying toy adopting this scheme has controllabledirection and good stability in flight, it requires the operator tocontrol the inclination and height of the propeller wing by using theremote control unit, so as to control the flying direction of the flyingtoy. For a flying toy, the remote control unit is added, and the cost ofthe flying toy will be higher. On the other hand, it is necessary tolearn how to operate the remote control unit, which also limits thepopularization audience of the flying toy. Furthermore, the flying toyfails to effectively protect the propeller component and the operator.When the flying toy collides with an obstacle, the propeller componenthas a great probability of being damaged, which leads to the loss of theflying ability of the flying toy. At the same time, the residual bladesof the propeller wings flying out due to the damage also have a greatprobability of hurting the operator. In the more extreme case, theflying toy flies out of control directly to the operator, resulting inmore serious situations. Any of the above problems is not ideal for theflying toy.

The prior art also discloses a flying toy which does not use a remotecontrol unit and simultaneously provides a protective shell for thepropeller. The U.S. patent application No. 20200238188 discloses aminiature finger gyro gyroplane, which comprises a main body casing, afan blade arranged in the main body casing, a mandrel arranged in thecenter of the fan blade, and a shiatsu upper cover and a shiatsu lowercover arranged at the upper and lower sides of the main body casingthrough both ends of the mandrel. The main body casing, the shiatsuupper cover and the shiatsu lower cover can rotate independently aroundthe mandrel, and are arranged in the main body casing.

Although the flying toy adopting this technical scheme does not need aremote control unit and is provided with a main body shell capable ofprotecting the propeller, when in use, it is necessary to first rotatethe main body shell and the fan blades, and the rotation direction ofthe main body shell and the fan blades is opposite to offset the torsionforce generated by the relative rotation between the main body shell andthe fan blades, so as to obtain sufficient lift force, and then theflying toy is thrown out, and the flying toy flies back by the gyroeffect. To throw the flying toy, you need to press the upper cover andthe lower cover with your hands first, and then throw the flying toy atan appropriate throwing angle. On the one hand, this throwing methodlimits the flying angle of the flying toy; on the other hand, becausethe main body shell is a part of the rotating flying component, thehigh-speed rotating shell may hurt the skin of the contact person, andeven cut your eyes in severe cases. At the same time, the flyingcomponent falling from high altitude will be broken if there is noprotection on the outside of the flying component. In addition, thehigh-speed rotating shell is also the main body of its gyro effect. Thisdesign only leaves two small finger pressure upper and lower covers. Theproducts produced by this technology are extremely difficult to operateand have poor user experience. Besides adults, the audience of flyingtoys is also a large number of operators. In the cognition of themajority of children, they do not know the principle of rotary flyingtoys. They only know that it is a toy that will fly back when thrownout. Therefore, it is necessary to throw out the flying toys by pressingthe cover, which further increases the difficulty for children to usethe flying toys. On the one hand, because the size of flying toys isfixed, it can't be suitable for children of different ages, such as thepalm of younger children.

Based on the above, it is necessary to provide a flying toy with fullenclosure isolation, which can isolate the flying components rotating athigh speed from the skin of the contact person, and at the same time,realize the technology of controlling different flight trajectories ofthe aircraft by preset throwing angles, which will make users have anincredible experience. When the flying toy falls from high altitude, thefully enclosed net shell can also protect the core flying components.

SUMMARY

The present invention provides a boomerang. The boomerang includes aflight component, wherein the flight component comprises at least onerotating device and a driving device; the maximum diameter rotatingplane formed by the rotation of the rotating device defines the outerperimeter of the flight component, and the rotating device rotatescoaxially around the center axis of the maximum diameter rotating plane;a central shaft penetrating the center axis, wherein two ends of thecentral shaft are respectively connected with a first base and a secondbase, and the first base and the second base are respectively separatedfrom the upper and lower ends of the flight component; a protectivedevice arranged around the flight component, wherein the protectivedevice is composed of a plurality of ribs connected with each other, andan inner diameter of the protective device corresponding to the outerperimeter of the flight component is larger than the outer perimeter.

In some embodiments, the center of the first base extends out of thefirst receiving part and receives the first end of the central shaft,and the center of the second base extends out of the second receivingpart to receive the second end of the central shaft. In order to improvethe protection effect of the ribs on the boomerang, the ribs areconfigured to be made of elastic materials. In order to make theboomerang have excellent rotary flying performance, the boomerang isconfigured to have two pairs of propellers which are arranged inparallel and rotate in opposite directions, and the propeller assembliesare started so that the boomerang can gain lift to fly.

At least one embodiment of the present invention relates to a boomerang.The boomerang comprises a first base, a second base, a luminouscomponent, a plurality of ribs extending outwards to connect the firstbase and the second base, and a central shaft connecting the flightcomponent to the first base and the second base, wherein the ribssurround the flight component, the first base and the second baserespectively receive the first end and the second end of the centralshaft, and the luminous component and the flight component areelectrically connected.

At least one embodiment of the present invention relates to a boomerang.The boomerang comprises a flight component, a central shaft and aprotective device, wherein the flight component comprises at least onerotating device, a driving device and a bracket with a cavity; thecentral shaft runs through the center axis of the maximum diameter planeformed when the rotating device rotates; and one end of the centralshaft is connected with a first base which is separated from the upperand lower ends of the flight component; and the protective device isformed by connecting a plurality of ribs.

BRIEF DESCRIPTION OF DRAWINGS

In order to explain the technical scheme of this application moreclearly, the following will briefly introduce the drawings that need tobe used in the embodiments. Obviously, the drawings in the followingdescription are only some embodiments of this application. For those ofordinary skill in this field, other drawings can be obtained accordingto these drawings without any creative effort.

FIG. 1 is a schematic diagram of a preferred embodiment of the presentinvention;

FIG. 2 is an explosion diagram of a preferred embodiment of the presentinvention;

FIG. 3 is a schematic diagram of the first base and ribs;

FIG. 4 is a schematic diagram of a second base and ribs;

FIG. 5 is a schematic diagram of the central axis;

FIG. 6 is a schematic diagram of the preferred embodiment of the presentinvention without flight components;

FIG. 7 is the explosion diagram of the flight component;

FIG. 8 is a schematic diagram of other extension tracks of ribs;

FIG. 9 is another schematic diagram of other extension tracks of ribs;

FIG. 10 is a schematic diagram of the use of other disclosedtechnologies;

FIG. 11 is a schematic diagram of the preferred embodiment of thepresent invention;

FIG. 12 is a schematic diagram of the center of gravity and the centerof lift of the preferred embodiment of the present invention;

FIG. 13 is a schematic diagram of a boomerang with a light emittingassembly according to the present invention;

FIG. 14 is a schematic diagram of a light emitting assembly;

FIG. 15 is a schematic diagram of the light emitting assembly of thepresent invention arranged on the propeller blade;

FIG. 16 is another schematic diagram of the central axis of the presentinvention;

FIG. 17 is a schematic diagram of the boomerang of the present inventionin flight;

FIG. 18 is a schematic diagram of the flight trajectory of the boomerangof the present invention;

FIG. 19 is another schematic diagram of the flight trajectory of theboomerang of the present invention;

FIG. 20 is another operation mode of the boomerang of the presentinvention;

FIG. 21 is a schematic diagram of a light source frame;

FIG. 22 is another embodiment of the boomerang of the present invention;

FIG. 23 is another embodiment of the boomerang of the present invention.

In the figures:

1. First base; 11. First receiving part; 2. Second base; 21. Secondreceiving part; 3. Rib; 4. Flight component; 401. Rotating device; 402.Driving device; 41. Propeller component; 42. Motor; 43. Motor base; 44.Power supply; 45. Sensor; 46. Circuit board; 47. Transmission gear; 48.Bracket; 411. First propeller; 412. Second propeller; 4121, Outer ring;4122. Installation table; 5. Central axis; 51. First end; 52. Secondend; 53. Shaft sleeve; 6. Luminous component; 61. Light bar; 62. Lightsource frame; 7. Accommodation space; 8. Protective device; G, center ofgravity; F, Lift center; F1, Thrust; F2, Wind power; F3, Lifting force;F4, offset force; S1, Flight trajectory; S2, Flight trajectory.

DESCRIPTION OF EMBODIMENTS

The technical solutions in the embodiments of this application will beclearly and completely described below with reference to the drawings inthe embodiments of this application. Obviously, the describedembodiments are only part of the embodiments of this application, butnot all of them. Based on the embodiments in this application, all otherembodiments obtained by ordinary technicians in this field withoutcreative labor are within the scope of protection in this application.

The reference to “an embodiment” or “an implementation” here means thata specific feature, structure or characteristic described in connectionwith an embodiment or an implementation can be included in at least oneembodiment of this application. The appearance of this phrase in variousplaces in the specification does not necessarily refer to the sameembodiment, nor is it an independent or alternative embodiment mutuallyexclusive with other embodiments. It is understood explicitly andimplicitly by those skilled in the art that the embodiments describedherein can be combined with other embodiments.

FIGS. 1 and 2 show a preferred embodiment of a boomerang, which includesa flight component 4 and a protective device 8 arranged around theflight component 4. The flight component 4 includes at least onerotating device 401 and a driving device 402. The maximum diameterrotation plane formed by the rotation of the rotating device 401 definesthe outer perimeter of the flight component 4, and the rotating device401 rotates coaxially around the center axis of the maximum diameterrotation plane.

The boomerang also includes a central shaft 5 (see FIG. 2 ) penetratingthrough the center axis of the maximum diameter rotating plane formed bythe rotation of the rotating device 401. Two ends of the central shaft 5are connected with the first base 1 and the second base 2, and the firstbase 1 and the second base 2 are separated from the upper and lower endsof the flight component 4.

Among them, the first base 1 extends from the center out of the firstreceiving part 11 (see FIG. 3 ), and the first receiving part 11 isconfigured to receive the first end 51 of the central shaft 5 (see FIG.5 ); The second base 2 extends from its center out of the secondreceiving part 21 (see FIG. 4 ), and the second receiving part 21 isconfigured to receive the second end 52 of the central shaft 5 (see FIG.5 ).

In this preferred embodiment, the central shaft 5 is preferably a singlethrough shaft with a cylindrical surface. In other embodiments, thecentral shaft 5 may also have surfaces of other shapes, such asrectangular or prismatic, and the central shaft 5 may also be composedof two or more mandrels through coupling. As shown in FIG. 16 , thecentral shaft 5 is composed of two coaxial mandrels, one end of which isrespectively received by the first receiving part 11 and the secondreceiving part 21, and the other end is rotatably connected with thebracket 48.

As shown in FIG. 1 and FIG. 2 , the protective device 8 arranged aroundthe flight component 4 is composed of a plurality of ribs 3 connected toeach other, and its inner diameter is larger than the outer periphery ofthe flight component 4.

In this preferred embodiment, between the first base 1 and the secondbase 2 receiving the central shaft 5, an accommodation space 7 (see FIG.6 ) is formed in the longitudinal axis direction of the central shaft 5,and the accommodation space 7 is designed to accommodate the flightcomponent 4. The accommodation volume of the accommodation space 7depends on the extension track of the ribs 3. Similarly, theaccommodation volume of the accommodation space 7 will also limit thesize of the flight component 4. In order to make the ribs 3 completelyprotect the flight component 4, the size of the flight component 4 isdesigned to be smaller than the accommodation volume of theaccommodation space 7.

FIG. 7 shows the main components of the flight component 4 of thepresent invention, including a rotating device 401 and a driving device402. The rotating device 401 is composed of a propeller component 41,which includes a first propeller 411 and a second propeller 412. Thedriving device 402 is composed of a motor 42, a motor base 43, a powersupply 44, a sensor 45, a circuit board 46 and a transmission gear 47,and the components of the driving device 402 are all built in a bracket48 with a cavity.

The second propeller 412 is fixedly connected to the motor base 43, themotor 42, the power supply 44 and the circuit board 46 are fixedlymounted on the motor base 43, and the sensor 45 is electricallyconnected to the circuit board 46. The sensor 45 feeds back signals tothe circuit board 46, and the circuit board 46 controls the operation ofthe motor 42. The driving shaft of the motor 42 is in transmissionconnection with the first propeller 411 through a transmission gear 47.

The motor 42 drives the first propeller 411 to rotate, and the reactionforce generated when the first propeller 411 rotates will push the motorbase 43 to rotate, thus driving the bracket 48 and the second propeller412 fixedly connected with the motor base 43 to rotate. At this time,the rotation direction of the bracket 48 and the second propeller 412 isopposite to that of the first propeller 411, so that the torsionalforces between the first propeller 411 and the second propeller 412 aremutually offset, and at the same time, the upward lift force isgenerated, so that the boomerang can fly. At the same time, under theaction of the thrown external force, the boomerang first flies in thethrowing direction for a certain distance. After the thrown externalforce disappears, the flying angle of the boomerang will remainunchanged due to the gyro effect generated by the rotation of thesupport 48 and the propeller, and the boomerang will continue to fly inthe direction of this angle. Users can preset the throwing angle of theboomerang to obtain different flight trajectories.

In order to make the flight component 4 fly with sufficient lift,besides increasing the RPM of the motor, it is also a preference to makethe blades of the propeller more similar. Increasing the size of thepropeller blades also increases the size of the flight component 4,which leads to the increase of the accommodating volume of theaccommodating space 7.

Increasing the accommodation volume of the accommodation space 7 can beachieved by increasing the extension length of the ribs 3. However, ifthe accommodation volume of the accommodation space 7 is simplyincreased by increasing the extension length of the ribs 3, the cost ofthe boomerang will undoubtedly increase greatly, which is obviously notideal.

On the premise of not increasing the extension length of the ribs 3, inorder to make the accommodation space 7 have the largest accommodationvolume, the extension track of the ribs 3 in this preferred embodimentis configured as y=±√{square root over ((r²−x²))} or x=±√{square rootover ((r²−y²))}. According to Euclidean geometry, when the circumferenceis the same, the surface area of a circle is the largest, and when thesurface area is the same, the volume of a sphere is the largest. Thedemonstration process of this basis is the existing academic knowledge,so it will not be discussed in this paper.

In some embodiments, the extension track of the ribs 3 can be othershapes, as shown in FIG. 8 , the extension track of the ribs 3 isy=ax²+bx+c: as shown in FIG. 9 , the extension tracks of the ribs 3 arey=kx+b and

$y = {\frac{k}{x}{( {k \neq 0} ).}}$

By analogy, the extension track of the rib 3 can be any desired shape.

As a preferred embodiment of the present invention, the extension trackof the rib 3 is configured as y=±√{square root over (r²−x²))} orx=±√{square root over ((r²−y²))}. With this configuration, the outercontour of the boomerang is closer to a regular sphere, and theoperation is more in line with the usage habits of operators.

As shown in FIG. 10 , the boomerang disclosed in U.S. patent applicationNo. 20200238188 adopts the operation mode of pressing the upper coverand the lower cover with two fingers and then throwing them out. In thisoperation mode, only the upper and lower covers of the boomerang arepressed by fingers, and the force can't be consistent when thrown, sothat the flight trajectory of the thrown boomerang has great uncertaintyand can't run according to the expected flight trajectory, which greatlyreduces the operator's actual use experience. Similarly, the number ofoptional flight trajectories of the boomerang is limited due to thelimitation of wrist joints.

As a preferred embodiment of the present invention, the presentinvention provides a boomerang, which throws the boomerang out of flightby grasping the boomerang with the palm. As shown in FIG. 11 , when inuse, the palm of the operator grasps the boomerang which forms anapproximate sphere. At this time, five fingers and palms are evenlydistributed on the surface of the boomerang. The central shaft 5installed on the first base 1 and the second base 2 of the protectivedevice 8 will balance the thrown external force on the central shaft 5,so as to ensure that the external force acting on the protective device8 will not change its angular momentum when the flight component 4rotates at a high speed. That is, when the boomerang provided by thepresent invention is thrown. Furthermore, with the grasping throwingform, there are more throwing paths that can be selected, more flighttrajectories of boomerangs, and a better user experience.

As shown in FIG. 17 , when the boomerang provided by the presentinvention tilts around the central axis 5, the flight component 4generates wind force F2 as shown in the figure, which can be dividedinto two parts: an offset force F4 and an ascending force F3; The offsetF4 will make the boomerang drift in one direction; The gyro effectgenerated by the first propeller 411 and the second propeller 412 of theflight component 4 keeps the deflection angle of the flight toy aboutthe central axis 5 from changing, and the flight toy will always fly inthis direction under the action of the deflection force F4.

FIG. 18 shows the flight trajectory of the boomerang provided by thepresent invention after being thrown out. When the operator preset theincluded angle with the central axis 5 as the axis, and the direction ofthe thrust F1 is opposite to that of the offset force F4, the boomerangis pushed out by the thrust F1. The gyro effect generated by the firstpropeller 411 and the second propeller 412 of the flight component 4keeps the offset angle of the boomerang with the central axis 5unchanged. When the thrust force F1 is greater than the offset force F4,the boomerang first flies along the flight path S1 in the direction ofthe thrust force F1, until the thrust force F1 disappears, and theboomerang flies along the flight path S2 at the corresponding offsetangle under the action of the offset force F4.

FIG. 19 shows another flight trajectory of the boomerang of the presentinvention. When the operator preset the included angle about the centralaxis 5, and the direction of the thrust F1 is the same as that of theoffset force F4, the boomerang is pushed out by the thrust F1. The gyroeffect generated by the first propeller 411 and the second propeller 412of the flight component 4 keeps the offset angle of the boomerang aboutthe central axis 5 unchanged, and the pushed thrust F1 is superimposedwith the offset force F4, and the boomerang will fly in the direction ofthe thrust F1.

In order to better protect the flight components 4 covered by the ribs3, the ribs 3 are configured to be made of elastic materials anddistributed crosswise. When the boomerang collides with an obstacle, theribs 3 made of elastic materials can produce elastic deformation, absorbthe corresponding collision energy, and provide buffer protection forthe flight component 4; Similarly, the cross distribution of the ribs 3further enhances the structural strength and reduces the probability offracture or damage of the ribs 3. At the same time, the ribs 3 can alsoprotect the operator, preventing the wings of the flight component fromflying out and causing harm to the operator.

In order to make the boomerang have better flying performance, the ribs3 are configured in a hollow grid shape to reduce the weight of the ribs3, and the grid pattern can be configured in any pattern shape; Thepropeller component 41 is configured as two pairs of first propellers411 and second propellers 412, which are arranged in parallel and rotatein opposite directions, so as to counteract the torsional forcegenerated when the propellers rotate; The rotating shafts of the firstpropeller 411 and the second propeller 412 are arranged coaxially withthe central shaft 5, so that the center of lift generated by thepropeller component 41 is on the same axis as the center of gravity ofthe boomerang.

The first propeller 411 is driven by the motor 42, and the reactionforce generated when the first propeller 411 rotates will push the motorbase 43 to rotate, and then drive the bracket 48 and the secondpropeller 412 fixedly connected with the motor base 43 to rotate. Atthis time, the rotation direction of the bracket 48 and the secondpropeller 412 is opposite to that of the first propeller 411, so thatthe torsional forces between the first propeller 411 and the secondpropeller 412 are mutually offset, and at the same time, lift force isgenerated, so that the boomerang can fly.

During the flying process of boomerangs, the position of the center ofgravity is also a factor affecting the flying stability. Once the centerof gravity shifts, it will lead to unstable flight trajectory, and makethe boomerang run on an unsatisfactory flight trajectory.

As a preferred embodiment of the present invention, the central shaft 5is configured to be coaxial with the rotating shafts of the firstpropeller 411 and the second propeller 412. This has the advantage thatthe center of gravity of the boomerang can be kept on the same axis asthe center of lift generated by the propeller component 41, and theangular momentum generated when the first propeller 411 and the secondpropeller 412 rotate will not change, so that the boomerang in operationwill have a gyro effect. After the boomerang is thrown, the flying angleof the boomerang remains unchanged due to the gyro effect generated bythe rotation of the bracket 48 and the propeller, and the boomerang willcontinue to fly along the direction of this angle. The user can presetthe throwing angle of the boomerang, so as to obtain different flighttrajectories.

According to the teaching of U.S. Pat. No. 6,843,699, when the center ofgravity is above the center of lift, the flying effect of boomerangswill increase. As shown in FIG. 12 , the propeller component 41 of thepresent invention is arranged below the motor base 43, and the liftingforce F3 generated by the propeller component 41 pushes the boomerangupward. At this time, the center of gravity G of the boomerang is abovethe lifting force center F generated by the propeller component 41, thusmaking the boomerang more stable in flight.

FIG. 13 shows another exemplary embodiment of a boomerang provided bythe present invention, which has all the technical features of thepreferred embodiment of the present invention. In order to make it moreornamental and playable, the boomerang also includes a light emittingcomponent 6.

As shown in FIG. 14 , the light emitting assembly 6 is configured as alight bar 61, which can be a flexible LED light bar, and is electricallyconnected with the circuit board 46 in the flight component 4. In orderto make the boomerang more enjoyable and playable, the bracket 48 isfurther provided with a light source bracket 62, which is designed tofix the light bar 61. The outer periphery of the second propeller 412 isformed with an outer ring 4121, and the outer ring 4121 is formed with amounting platform at its end edge. The mounting table 4122 is alsodesigned to fix the light bar 61, wherein the light bar 61 is designedto rotate synchronously with the bracket 48, and the radius of rotationcoincides with the maximum rotation radius of the rotating device 401.At the same time, the circuit board 46 can control differentlight-emitting units on the light bar 61, so as to realize stereoscopiclight picture display during rotation.

Specifically, as shown in FIGS. 14 and 21 , the light source bracket 62is arranged below the first propeller 411 and sleeved on the centralshaft 5. One end of the light bar 61 is electrically connected with thecircuit board 46, the other end is fixedly connected with the lightsource bracket 62, and the middle part is fixedly connected with themounting table 4122. The light source bracket 62 can rotate relative tothe axis of the central shaft 5, so when the bracket 48 rotates, thebracket 48 will drive.

In this embodiment, the outer periphery of the second propeller 412 isformed with an outer ring 4121, the radius of which is larger than therotation radius of the blades of the second propeller 412, and the outerring 4121 is fixedly connected with the bracket 48 through the blades ofthe second propeller 412. On the one hand, the outer ring 4121 canprotect the blades of the second propeller 412 and increase the safetyof the flight component 4; on the other hand, the outer ring 4121fixedly connected with the bracket 48 can also increase the flightrotation of the boomerang.

In order to make the boomerang have other types of light and shadoweffects, the position of the lighting assembly 6 can be set according tothe actual requirements. FIG. 15 shows that the lighting assembly 6 isarranged on the propeller blade, which also adopts the LED light barmade of flexible material, which can also make the boomerang havedynamic light and shadow visual effects. As shown in FIG. 16 , theposition of the light-emitting component 6 can also be arranged on therib 3. As the light-emitting component 6 is arranged on the outersurface of the rib 3, the light emitted by the light-emitting component6 is not blocked by the rib 3. The boomerang has more realistic visualeffect and better appreciation. In addition, the light-emittingcomponents 6 can be configured in various ways, including but notlimited to thermal radiation light sources, gas discharge light sources,electroluminescent light sources, etc., and their positions can also bearranged inside or outside the ribs 3 according to the actual userequirements, and the number of them can also be configured in multipleways, or their light-emitting effects can be controlled independently,without linkage with the flight components 4.

Now, referring to FIG. 20 , the boomerang provided by the presentinvention has other playing methods besides the throwing method. Theuser can place the boomerang on the palm of his hand. When the wind F2of the boomerang puts pressure on the palm of his hand, the palm of hishand also gives the boomerang a reaction force, so that the boomerangcan be suspended above the palm of his hand.

FIG. 22 shows another embodiment of the present invention. As shown inFIG. 21 , the boomerang includes a flight component 4, a central shaft 5and a protective device 8. The flight component 4 includes at least onerotating device 401, a driving device 402 and a bracket 48 with acavity, wherein the maximum diameter rotating plane formed by therotating device 401 when rotating defines the outer perimeter of theflight component 4, and the rotating device 401 rotates coaxially aroundthe center axis defined by the maximum diameter rotating plane. Thecenter shaft 5 coincides with the center axis, and one end of the centershaft 5 is connected with the first base 1, which is separated from theupper and lower ends of the flight component 4; The protective device 8is composed of a plurality of ribs 3 connected to each other, and isarranged around the flight component 4, wherein the inner diameter ofthe protective device 8 is larger than the outer periphery of the flightcomponent 4.

Different from the preferred embodiment of the present invention, inthis embodiment, the second end 52 of the central shaft 5 is notreceived by the second base 2, but a sleeve 53 is sleeved on the secondend 52. The sleeve 53 is tightly connected with the second end, and thesleeve 53 can keep the rotating shaft of the rotating device 401 coaxialwith the central shaft 5. The boomerang adopting this scheme also hasgood flying performance and can also protect the flight component 4.

FIG. 23 shows another embodiment of the present invention, which adoptsthe same main structure as the embodiment shown in FIG. 22 , and thedifference is the design angle of the second propeller 412 blade. Asshown in FIG. 23 , the concave surface of the blade of the secondpropeller 412 of the rotating device 401 faces the driving device 402.This arrangement can also make the boomerang have better flyingperformance and playability.

The technical means disclosed in the scheme of the present invention isnot limited to the technical means disclosed in the above embodiments,but also includes the technical scheme composed of any combination ofthe above technical features. It should be pointed out that for those ofordinary skill in the technical field, several improvements andembellishments can be made without departing from the principle of thepresent invention, and these improvements and embellishments are alsoregarded as the protection scope of the present invention.

What is claimed is:
 1. A boomerang, comprising: a flight component,wherein the flight component comprises at least one rotating device, adriving device and a bracket with a cavity, and the cavity of thebracket is internally provided with a motor, a power supply, and a powersupply; a maximum diameter rotation plane formed by the rotation of therotating device defines the outer perimeter of the flight component, andthe rotating device rotates coaxially around a center axis defined bythe maximum diameter rotation plane; a central shaft coinciding with thecenter axis, wherein the two ends of the central shaft are respectivelyconnected with a first base and a second base, and the first base andthe second base are respectively separated from the upper and lower endsof the flight component; a protective device arranged around the flightcomponent, wherein the protective device is composed of a plurality ofribs connected with each other, and an inner diameter of the protectivedevice corresponding to the outer perimeter of the flight component islarger than the outer perimeter.
 2. The boomerang according to claim 1,wherein the protective device has a hollow surface.
 3. The boomerangaccording to claim 2, wherein the ribs are made of elastic materials. 4.The boomerang according to claim 1, wherein the rotating device iscomposed of a first propeller and a second propeller, and the rotationdirections of the first propeller and the second propeller are opposite.5. The boomerang according to claim 4, wherein an outer periphery of thesecond propeller is formed with an outer ring, and a radius of the outerring is larger than a rotating radius of blades of the second propeller.6. The boomerang according to claim 5, wherein the outer ring is fixedlyconnected with the bracket through the blades of the second propeller.7. The boomerang according to claim 6, further comprising a light barelectrically connected with the circuit board.
 8. The boomerangaccording to claim 7, wherein one end of the light bar is fixedlyconnected with an upper end of the bracket, the other end of the lightbar is fixedly connected with a lower end of the bracket, and the lightbar rotates synchronously with the bracket.
 9. A boomerang, comprising:a flight component, wherein the flight component comprises at least onerotating device, a driving device and a bracket with a cavity; a maximumdiameter rotation plane formed by the rotation of the rotating devicedefines an outer perimeter of the flight component, and the rotatingdevice rotates coaxially around a center axis defined by the maximumdiameter rotation plane; a central shaft coincident with the centeraxis, wherein one end of the central shaft is connected with a firstbase, and the first base is separated from the upper and lower ends ofthe flight component; a protective device arranged around the flightcomponent, wherein the protective device is composed of a plurality ofribs connected with each other, and an inner diameter of the protectivedevice corresponding to the outer perimeter of the flight component islarger than the outer perimeter.